00001 /*This file is prepared for Doxygen automatic documentation generation.*/ 00015 /* Copyright (c) 2009 Atmel Corporation. All rights reserved. 00016 * 00017 * Redistribution and use in source and binary forms, with or without 00018 * modification, are permitted provided that the following conditions are met: 00019 * 00020 * 1. Redistributions of source code must retain the above copyright notice, this 00021 * list of conditions and the following disclaimer. 00022 * 00023 * 2. Redistributions in binary form must reproduce the above copyright notice, 00024 * this list of conditions and the following disclaimer in the documentation 00025 * and/or other materials provided with the distribution. 00026 * 00027 * 3. The name of Atmel may not be used to endorse or promote products derived 00028 * from this software without specific prior written permission. 00029 * 00030 * 4. This software may only be redistributed and used in connection with an Atmel 00031 * AVR product. 00032 * 00033 * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED 00034 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00035 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE 00036 * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR 00037 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 00038 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 00039 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 00040 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 00041 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 00042 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE 00043 * 00044 */ 00045 00046 #include "dsp.h" 00047 00048 #define WIN_HANN_A0 0.5 00049 00050 #if defined(FORCE_ALL_GENERICS) || \ 00051 defined(FORCE_GENERIC_WIN16_HANN) || \ 00052 !defined(TARGET_SPECIFIC_WIN16_HANN) 00053 00054 // Hann 00055 // w(n) = 0.5*(1-cos(2*PI*n/(N-1))) 00056 // avec 00057 // N = signal width 00058 void dsp16_win_hann(dsp16_t *vect1, int size) 00059 { 00060 S32 w; 00061 dsp16_t s, t; 00062 int i; 00063 00064 // Initialization 00065 t = DSP16_Q(0.); 00066 // Calculation of 2/(N-1) <- because a cos is in the range [-1; 1], 00067 // therefore -1 equals -PI and 1, PI. 00068 s = (DSP16_Q(1.)/(size - 1)) << 1; 00069 00070 // Compute the window 00071 for(i=0; i<(size >> 1); i++) 00072 { 00073 w = DSP16_Q(1.); 00074 w -= (S32) dsp16_op_cos(t); 00075 w = (w*((S32) DSP16_Q(WIN_HANN_A0))) >> DSP16_QB; 00076 vect1[i] = w; 00077 vect1[size-i-1] = w; 00078 t += s; 00079 } 00080 00081 // If the size is odd 00082 if (size & 1) 00083 vect1[size >> 1] = DSP16_Q(1.); 00084 } 00085 00086 #endif 00087 00088 #if defined(FORCE_ALL_GENERICS) || \ 00089 defined(FORCE_GENERIC_WIN32_HANN) || \ 00090 !defined(TARGET_SPECIFIC_WIN32_HANN) 00091 00092 void dsp32_win_hann(dsp32_t *vect1, int size) 00093 { 00094 S64 w; 00095 dsp32_t s, t; 00096 int i; 00097 00098 // Initialization 00099 t = DSP32_Q(0.); 00100 // Calculation of 2/(N-1) <- because a cos is in the range [-1; 1], 00101 // therefore -1 equals -PI and 1, PI. 00102 s = (DSP32_Q(1.)/(size - 1)) << 1; 00103 00104 // Compute the window 00105 for(i=0; i<(size >> 1); i++) 00106 { 00107 w = DSP32_Q(1.); 00108 w -= (S64) dsp32_op_cos(t); 00109 w = (w*((S64) DSP32_Q(WIN_HANN_A0))) >> DSP32_QB; 00110 vect1[i] = w; 00111 vect1[size-i-1] = w; 00112 t += s; 00113 } 00114 00115 // If the size is odd 00116 if (size & 1) 00117 vect1[size >> 1] = DSP32_Q(1.); 00118 } 00119 00120 #endif